LAwn sprinklers and air in the line

Remove the head from the last sprinkler in that section. Turn on the water. Wait for all the air to leave the system. Turn off the water. Put the head back on.

Repeat for other zones just for fun. :)

Why wouldn't the air just leave anyway through normal operation? Most sprinkler systems have some air in them and it all comes out each time they start up.

Is this only a temporary problem during start-up of that zone or are you saying it's continuous? If it's continuous, it sounds more like some kind of problem with the control valve on that zone to me.

Thanks. I appreciate the reply. Is repeating the other zones really just fun or is there a reason I should do it for preventative or other reasons.

Iff'n it were my system, I'd do all the zones. Besides getting air out of the system, you'll flush out any accumulated debris that might later clog sprinkler heads.

When clients ask me to fix a problem where one piece of a system is causing a problem, I suggest doing all the pieces as preventive maintenance. For example, if they want one water heater flushed, I suggest we do both (in a two-WH house).

I went out today, turned on the sprinkler so I get at the head and take it off, and the problem went away on its own.